Method of connecting electric wires

ABSTRACT

The object is to provide a method of connecting covered wires mutually which can solve cost increasing.  
     Each of covered wires  2, 3  is comprised of each conductor  4, 10  and each cover  5, 11 . The covered wires  2, 3  are connected to each other by ultrasonic welding. A ultrasonic welding machine includes a chip and an anvil. The covered wires  2, 3  are placed between the chip and the anvil, crossing one on other. The chip is located as the length of cross section is along the length of other covered wire  3 . The chip and the anvil are pushed to be closer to each other and the chip is vibrated. Friction heat is generated between the covered wires  2, 3 . The covers  5, 11  are adhered together and the conductors  4, 10  are metallic bonded in solid condition without melting. In short, the conductors  4, 10  are bonded to each other by so-called ultrasonic welding.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention This invention relates to a method of connecting plural covered wires to each other.

[0002] 2. Description of the Related Art

[0003] In an automobile as a transferring object, a wiring harness is provided to supply electric power of a battery to installed electronic devices such as various lamps and motors and send control signals of a control unit to the electronic devices. The wiring harness has plural covered wires or the like. At least some of plural wires, comprising the wiring harness, are required to connect to each other.

[0004] When connecting conductors of the covered wires to each other, firstly cover of the wire is removed at a connecting point. After that, the conductors are connected by welding like resistance welding. Or, as other connection method, pressure contact or crimp contact with other conductive metal parts, different from the conductor, is used to connect the conductors of the covered wires to each other.

[0005] Methods of connecting covered wires mutually by prior art, as mentioned above, require removing the cover of covered wires and then it makes man-hour for work operations increase. Further, using additional other metal part makes number of parts increase. Therefore, methods of connecting covered wires by prior art make cost increase.

SUMMARY OF THE INVENTION

[0006] This invention has been accomplished to overcome the above drawbacks and an object of this invention is to provide a method of connecting covered wires mutually which can solves cost increasing.

[0007] In order to attain the objects, a method of connecting covered wires according to this invention is comprised of the steps of placing a covered wire on the other covered wires and welding conductors of covered wires to each other by ultrasonic welding.

[0008] In the method of connecting covered wires, as mentioned above, the covers of each covered wire are adhered to each other by the above ultrasonic welding.

[0009] In the each method of connecting covered wire, as mentioned above, one covered wire and other covered wire are clamped by a chip and an anvil, correspondingly and mutually, of an ultrasonic welding machine and said chip is placed with straddling form on one covered wire and the covered wires are connected by ultrasonic welding.

[0010] Since the connection of the covered wires according to this invention is done by ultrasonic welding in condition of placing a covered wire on the other covered wires, removing the cover on the connection point of the covered wires is not required to connect covered wires to each other. Since the covered wires are ultrasonic welded mutually one upon another, other metallic parts different from the covered wires are not required to connect the covered wires to each other. The covered wire, which has round shape cross section, is preferable. In case of the wire with round shape cross section, the cover is removed securely from a gap between each conductor by ultrasonic welding. Therefore, the method can perform to connect each conductor securely without operation of removing the cover.

[0011] Advantageously, in the above method of connecting covered wires mutually according this invention, since the cover is adhered to each other by ultrasonic welding, mechanical strength of the point where conductors are connected mutually can be improved. Further, since cover is adhered to each other, the conductors can be connected securely to each other without operation of removing the covers.

[0012] Advantageously, in the above method of connecting electric wires mutually according this invention, the chip of an ultrasonic machine is placed with straddling form on one covered wire. Therefore, the conductor of one covered wire, which the chip contacts on, is pushed securely toward the conductor of the other covered wire and connecting conductors to each other can be done more securely. In this method of connecting electric wires, the chip may be formed in both of larger or smaller than the larger diameter of one covered wire which the chip contacts by ultrasonic welding or the other covered wire along the radius direction of the covered wire.

[0013] Preferably, in this method, the chip is formed in strip shape. When one covered wire and the other covered wire, as mentioned above, cross to each other one upon another, the cross section of the chip along the length of the covered wire may cross to one of the covered wires to be contacted by ultrasonic welding and be along the length of other.

[0014] In this condition of two covered wires crossing to each other, the chip contacts one covered wire along the length of the covered wire and crosses to the other covered wire. Then, the top of the chip dents one covered wire that the chip contacts. Therefore, the chip can press securely the conductor of one contacted covered wire toward the conductor of the other covered wire, and connect tightly the conductors to each other.

[0015] In the condition of placing one covered wire and other covered wire in parallel one upon another, the length of the strip shape chip on the cross section along the length direction of the covered wires is aligned preferably along the length of the covered wires which are placed in parallel one upon another. In this case, the thickness, perpendicular to the length of the chip on the cross section along the length direction of the covered wires, may be both of larger or smaller than the diameter of the covered wires.

[0016] The chip is placed as the length of the chip is along the length direction of parallel covered wires to each other, stacked one on another. The top of the chip dents one covered wire that the chip contacts. Therefore, the chip can press securely the conductor of one contacted covered wire toward the conductor of the other covered wire, and connect tightly the conductors to each other.

EFFECT of INVENTION

[0017] As mentioned above, according to claim 1 of this invention, a conductors can be bonded to each other without operation of removing cover, since covered wires are connected mutually by ultrasonic welding. Other metal parts, different from these covered wires, are not required to connect covered wires mutually since covered wires are connected mutually one upon another by ultrasonic welding. Therefore, man-hours and number of parts for connecting the covered wires 2, 3 can be reduced and the cost also can be reduced.

[0018] According to claim 2 of this invention, cost reduction for connecting covered wires mutually can not be done only, but mechanical strength on connecting point of covered wires can also be improved, since covers are adhered to each other when connecting the wires by ultrasonic welding.

[0019] According to claim 3 of this invention, a chip is located to saddles on one covered wire which is contacted by the chip in case of crossing covered wires one upon another to each other. Therefore, the chip pushes more securely a conductor of above one covered wire, contacted by the chip, toward a conductor of other covered wire. Then, man-hours and number of parts for connecting the covered wires 2, 3 can not be only reduced but conductors can be also bonded more tightly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is a perspective view of covered wires connected by method of connecting electric wires according to the first embodiment of this invention;

[0021]FIG. 2 is a sectional view taken along the line II-II of FIG. 1;

[0022]FIG. 3 is a sectional view of one appearance before connecting covered wires to each other in this embodiment;

[0023]FIG. 4 is a sectional view seen from an arrow IV of FIG. 3;

[0024]FIG. 5 is a sectional view of one appearance after connecting covered wires to each other in this embodiment;

[0025]FIG. 6 is a drawing for explaining the method of connecting electric wires in this embodiment, to show covered wires, a chip, vibrating direction of the chip and others as a model;

[0026]FIG. 7 is a perspective view of covered wires connected by method of connecting electric wires according to the second embodiment of this invention;

[0027]FIG. 8 is a sectional view taken along the line VIII-VIII of FIG. 7;

[0028]FIG. 9 is a sectional view of one appearance before connecting covered wires to each other in this embodiment;

[0029]FIG. 10 is a sectional view of one appearance after connecting covered wires to each other in this embodiment;

[0030]FIG. 11 is a drawing for explaining the method of connecting electric wires in this embodiment, to show covered wires, a chip, vibrating direction of the chip and others as a model;

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0031] A structure of connecting mutually covered wires as the first embodiment according to this invention will now be described with reference to FIG. 1 or FIG. 6. The connecting structure as the embodiment according to this invention is to connect one covered wire 1 and other covered wire 3 to each other, as shown in FIG. 1 or FIG. 2.

[0032] The covered wire 2 is formed into round shape cross section. The covered wire 2 includes a conductor 4 with round shape cross section and a cover 5 for covering the conductor 4. The conductor 4 is flexible wire and made of electrical conductive metal. The conductor 4 includes at least copper or copper alloy. The cover 5 is flexible and made of electric non-conductive synthetic resins such a polyvinylchloride (PVC) or the like.

[0033] The covered wire 3 is formed into round shape cross section. The covered wire 3 includes a conductor 10 with round shape cross section, and a cover 11 for covering the conductor 10. The conductor 10 is flexible wire and made of electrical conductive metal. The conductor 10 includes at least copper or copper alloy. The cover 11 is flexible and made of electric non-conductive synthetic resins such a polyvinylchloride (PVC) or the like. The cover wires 2, 3 have the same wire diameter as an example, shown in the drawing.

[0034] The covered wires 2, 3 are placed one upon another, to cross to each other, as shown in FIG. 1, 2. And at a connecting point of each area 2 a, 3 a, the cover 5, 11 are adhered to each other and the conductors 4, 10 are connected to each other in condition of metallic bonding. In this drawing as an example, the covered wires 2, 3 cross to each other and are connected to each other by an ultrasonic welding machine. And in this drawing, the connecting point of area 2 a, 3 a are located in the center of the length of the covered wire 3.

[0035] The ultrasonic welding machine includes a chip 20, an anvil 21 corresponding to the chip 20 and a not-shown oscillator, vibrator, a cone, a horn. The chip 20 is formed into strip shape. In this example of the chip 20, the width W (shown in FIG. 3) is formed to be larger than the outer diameters of the covered wires 2, 3. In this invention, the width W (shown in FIG. 3) formed smaller than the outer diameters of the covered wires 2, 3 is also effective. The width W is a length of the cross section of the chip 20 along the length of the covered wire 2, 3 when connecting to each other, describing more later. The width W is a length along the radius direction of the covered wire 2, describing later. The anvil 21 is provided with a flat surface on which welding objects can be placed.

[0036] In the ultrasonic welding machine, objects to be welded mutually are clamped between the chip 20 and the anvil 21. Pressing the objects by the chip 20 and the anvil 21 to be closer mutually, the vibrator is vibrated by the oscillator and the vibration through the cone and the horn is transmitted to the chip 20. Then, the ultrasonic welding machine supplies ultrasonic vibration on the welding objects, clamped between the chip 20 and the anvil 21, and welds the objects by frictional heating.

[0037] To connect the covered wires 2, 3 to each other in crossing figure, the covered wires 2, 3 are clamped between the chip 20 and the anvil 21, as shown in FIG. 3, 4. In this moment, the covered wires 2, 3 cross to each other and are placed one upon another at area 2 a, 3 a. And the chip 20 contacts area 2 a of the covered wire 2, one of the covered wires 2, 3.

[0038] The chip 20 is aligned as the length of its cross section along a plane by the covered wires 2, 3 crosses one of the covered wire 2 and is placed along other covered wire 3, as shown in FIG. 3 or 6. In the drawing as an example, the chip 20 is aligned as the length crosses the covered wire 2 and is placed along the covered wire 3.

[0039] Furthermore, the chip 20 is located as one covered wire 2 is placed between both edges 20 a, 20 b along the length of the covered wire. And the chip 20 is located as the both edges 20 a, 20 b are juxtaposed along the radius direction of one covered wire 2. In short, the chip 20 is located as saddling on the covered wire 2. In the drawing as an example, the chip 20 is located as the both edges 20 a, 20 b saddles on one covered wire 2.

[0040] The chip 20 and the anvil 21 are pushed near to each other in direction of arrows P1, P2 shown in FIG. 3. Then, the top of the chip 20 dents the area 2 a of the covered wire 2 which the top of the chip 20 contacts. After that, vibration of the vibrator, vibrated by the oscillator is transmitted to the chip 20 through the cone and the horn.

[0041] Since the area 2 a, contacted with the top of the chip 20, of the covered wire 2 is dented, one covered wire 2 is vibrated together with the chip 20. Friction heat complied with the vibration level is given between the covered wires 2, 3 and the covers 5, 11 are melted.

[0042] Since the chip 20 and the anvil 21 are pushed near to each other and the covers 5, 11 are melted, the conductors 4, 10 are contacted mutually. When contacting the conductors to each other, the conductors 4, 10 are metallic bonded together without melting by above friction heat. In other words, the conductors 4, 10 is connected mutually by the so-called ultrasonic adhesion (ultrasonic welding or ultrasonic bonding). Since the covers 5, 11 are adhered mutually and the conductors 4, 10 are bonded together, the covered wires 2, 3 are connected to each other.

[0043] In the embodiment according to this invention, the covers 5, 11 are adhered mutually and the conductors 4, 10 are bonded together by ultrasonic welding. Therefore, operation for removing cover is not required and other metal parts also are not required to connect the covered wires 2, 3. Then, man-hours and number of parts for connecting the covered wires 2, 3 can be reduced and the cost also can be reduced.

[0044] The covers 5, 11 are adhered to each other at the area 2 a, 3 a which are connecting point of the covered wires 2, 3. Then, the mechanical strength on connecting point of the covered wires 2, 3 can be improved. Therefore, the covered wires 2, 3 are connected tightly.

[0045] The chip 20 is located as the length of the chip cross section crosses one covered wire 2 and saddles on this covered wire 2. Therefore, the chip 20 can push securely the conductor 4 toward other covered wire 3. Then, the conductors 4, 10 are bonded securely and the covered wires 2, 3 are connected tightly.

[0046] Since the chip 20 dents one covered wire 2, the covered wire 2 is vibrated securely together with the chip 20. Then, the conductors 4, 10 are bonded together securely and the covered wires 2, 3 can be connected more tightly.

[0047] The second embodiment of method of connecting electric wires according to this invention will now be described with reference to FIG. 7 or FIG. 11. The same comprising parts as the first embodiment, mentioned above, are assigned with the same marking and explanation on the parts is not omitted.

[0048] In this embodiment, the covered wires 2, 3 are connected in parallel one upon another mutually. In the drawing as an example, the covered wires 2, 3 are stacked in parallel one upon another. In this embodiment, the covers 5, 11 are adhered to each other at the area 2 a, 3 a and the conductors 4, 10 are connected mutually by metallic bonding, as mentioned on the first embodiment, as shown in FIG. 8.

[0049] In this embodiment, the covered wires 2, 3 are connected to each other by ultrasonic welding machine as mentioned on the first embodiment. Firstly, to connect the covered wires 2, 3 to each other in parallel, the covered wires 2, 3 are clamped at area 2 a, 3 a between the chip 20 and the anvil 21, as shown in FIG. 9. In this moment, the chip 20 are placed as the length of the cross section is juxtapositional along the length of the covered wires 2, 3. In this embodiment, the thickness T (shown in FIG. 9, 10) of the chip 20, in perpendicular direction for the length of the cross section along the covered wires 2, 3, may be larger or smaller than the outer diameters of the covered wires 2, 3.

[0050] In the next, the chip 20 and the anvil 21 are pushed near to each other in direction of arrows P1, P2 shown in FIG. 9. The top of the chip 20 dents the area 2 a of the covered wire 2 which the top of the chip 20 contacts. Vibration of the vibrator, vibrated by the oscillator is transmitted to the chip 20 and the chip 20 is vibrated. One covered wire 2 is vibrated together with the chip 20 and friction heat is given between the covered wires 2, 3.

[0051] The covers 5, 11 are melted by above friction heat. When the covers 5, 11 are melted, the conductors 4, 10 are contacted to each other as shown in FIG. 10. When contacting the conductors to each other, the conductors 4, 10 are metallic bonded together without melting by above friction heat. In other words, the conductors 4, 10 is connected mutually by the so-called ultrasonic adhesion (ultrasonic welding or ultrasonic bonding) Since the covers 5, 11 are adhered mutually and the conductors 4, 10 are bonded together, the covered wires 2, 3 are connected to each other.

[0052] In the embodiment according to this invention, the covers 5, 11 are adhered mutually and the conductors 4, 10 are bonded together by ultrasonic welding and then the covered wires 2, 3 are connected to each other, as mentioned on the first embodiment. Therefore, man-hours and number of parts for connecting the covered wires 2, 3 can be reduced and the cost also can be reduced. Furthermore, the mechanical strength on connecting point of the covered wires 2, 3 can be improved and then the covered wires 2, 3 can be connected tightly.

[0053] In this embodiment, the chip 20 is located as the length of the chip is along the covered wires 2, 3. Since the chip 20 dents the covered wire 2, the chip 20 can vibrate the covered wire 2 securely. Therefore, the chip 20 can push securely the covered wires 2, 3 near to each other and the conductors 4, 10 are bonded to each other.

[0054] In the first and second embodiments, since each of the covered wires 2, 3 is formed into round shape cross section, the pressing force, loaded on the chip 20 and the anvil 21 in direction of arrows P1, P2, concentrates on a mutual contact point of the covered wires 2, 3. Therefore, the covers 5, 11 are removed securely from a gap between the conductors 4, 10. Then, the conductors 4, 10 can be bonded tightly to each other without operation of removing the covers on the covered wires 2, 3.

[0055] In the embodiments, mentioned above, the covered wires 2, 3 having each of the conductors 4, 10 as single core wire are connected. In this invention, connecting mutually plural covered wires formed with cover and stranded conductor by stranding plural conductors is also effective. In such a case, the stranded conductors are bonded to each other. 

What is claimed is:
 1. A method of connecting electric wires comprising the steps of; placing one covered wire on the other covered wires; and welding conductors of covered wires to each other by ultrasonic welding.
 2. The method of connecting electric wires according to claim 1, wherein covers of respective covered wires are adhered to each other by ultrasonic welding.
 3. The method of connecting electric wires according to claim 1 or 2, wherein the covered wires are clamped by a chip and an anvil, correspondingly and mutually, of an ultrasonic welding machine, wherein said chip is placed with straddling form on one covered wire. 